This invention relates to a fluorescent display device comprising a plurality of substantially aligned anode units, each composed of a predetermined number of segmented fluorescent anodes arranged in a preselected configuration. It should be noted here that fluorescence is not much different from phosphorescence and that the word "fluorescent" is used throughout the instant specification to cover the concept of luminescence emitted by a phosphorescent material with a shorter period.
In general, a display device of the type described comprises a plurality of grids opposite the respective anode units and a hot cathode over the grids to provide a visual display of at least one numeral together with or without a decimal point, at least one alphabet, or the like. Such a device will herein be called a multidigit fluorescent display device. When the device is driven in a time-division fashion, the grids are driven preferably cyclically. The segmented anodes are selectively driven in one of the anode units that is opposite the grid being energized. It is a tendency in a recent multidigit fluorescent display device that the grids are rendered narrow in the direction of alignment. In a device of the recent type, each digit does not luminesce with a uniform brightness. This results from an undesired influence of adjacent grid or grids as will later be described with reference to a few figures of the accompanying drawing.